and, given that its primary symptoms may be found in various other disorders, differential diagnosis can be problematic. ... delusional thinking or substance abuse was re- .... American Psychiatric Association Diagnostic and statistical manual.

DOI: http://dx.doi.org/10.1590/abd1806-4841.20187693 Abstract: Infantile hemangioma can be linked to other organ malformations. In 1996, PHACE syndrome was first defined as the association of large and segmental infantile hemangioma, usually on the face, head, or cervical region, with malformations of the posterior fossa of the brain, arterial anomalies of the central nervous system, coarctation of the aorta, cardiac defects, and ocular abnormalities. Over 300 cases of PHACE syndrome have been reported, and it is cconsidered one of the most common neurocutaneous vascular disorders in childhood. Knowledge of the features and locations of lesions that imply a greater risk of systemic involvement is crucial for the diagnosis and proper management of PHACE syndrome patients. This review highlights the diagnostic criteria for PHACE syndrome, the imaging workup for extracutaneous involvement, the treatment of infantile hemangioma, and the importance of a multidisciplinary approach in the management of these patients. Keywords: Aortic coarctation; Hemangioma; Magnetic resonance imaging; Neurocutaneous syndromes; Propranolol; Stroke

INTRODUCTION Infantile hemangioma (IH) is the most frequent benign tumor in the pediatric population, with an incidence of 5% to 10%.1 These tumors usually do not present with systemic involvement. In cases of extensive and segmental IH, especially on the face, scalp, and cervical region, a clinical and imaging workup is recommended to detect the changes that are described in PHACE syndrome.2 The most remarkable feature of PHACE syndrome is IH, but abnormalities in the brain, aortic, thoracic, and cervical arteries, which are not obvious on clinical examination, have considerable potential for morbidity.3,4 DEFINITION OF PHACE SYNDROME The first description of the association of PHACE syndrome with brain abnormalities was reported in 1978 by Pascual-Castroviejo.5 In 1996, Frieden et al. created the acronym PHACE (posterior fossa malformations, hemangioma, arterial anomalies, coarctation of the aorta/cardiac defects, and eye abnormalities) to detail the most represen-

tative features of the syndrome.6 Subsequently, sternal malformations was added, giving rise to the acronym PHACES.7 In 2009, the diagnostic criteria for PHACE syndrome were established 8 and then revised in 2016 by Garzon et al.3 It is a neurocutaneous condition in which extensive or segmental IH, usually on the face, scalp, or cervical region, can be associated with posterior fossa malformations, arterial abnormalities [primarily in the central nervous system (CNS)], coarctation of the aorta, cardiac defects, and ocular abnormalities.6 PREVALENCE PHACE syndrome is observed in 2% to 3% of IH cases. There are over 300 cases in the literature, and it is considered one of the most frequent neurocutaneous vascular disorders in childhood. According to several studies, when the IH develops on the face and is segmental or large, the likelihood of it being associated with PHACE syndrome is 20% to 31%. PHACE syndrome affects

females more frequently (9:1). Infantile hemangioma (most cases), cerebrovascular (83% to 91%) and cardiac (41% to 67%) changes are among its most common manifestations.2,9,10 PATHOGENESIS The pathogenesis of PHACE syndrome is unknown. It has been postulated to result from defective embryogenesis between weeks 3 and 12 of gestation, before or during vasculogenesis, because certain malformations and IH can affect the same side of the body.11 There is no evidence of genetic abnormalities that contribute to the development of PHACE syndrome.12

of ocular and CNS involvement, whereas those on the mandibular segment are linked to a greater risk of midline and cardiovascular defects (Figures 1 to 4).11 Chart 1: Diagnostic criteria for PHACES syndrome System

Major criteria

Minor criteria

Brain (vascular)

Anomalies of larger brain vessels

Persistence of embryonic arteries

Arterial dysplasia, stenosis or occlusion

Proatlantal intersegmental artery

Absence or hypoplasia

Primitive hypoglossal artery

Aberrant origin or course

Primitive ophthalmic artery

DIAGNOSTIC CRITERIA In 2009, a group of various specialties (dermatology, neurology, oncology, genetics, cardiology, and ophthalmology) established criteria for the diagnosis of PHACE syndrome, stratifying it into 2 categories: 1. PHACE syndrome, defined by the presence of segmental IH larger than 5cm on the face, scalp, or cervical region, associated with 1 major criterion or 2 minor criteria. 2. Possible PHACE syndrome, defined by the presence of IH and 1 minor criterion. Major and minor criteria have been determined, based on the vascular and structural involvement of the brain, cardiovascular system, eye, and midline (Chart 1). 8 In 2016, new recommendations for the diagnosis and follow-up of patients with PHACE syndrome were published by a multidisciplinary group, comprising neuroradiology, neurosurgery, neurology, cardiology, cardiothoracic surgery, dermatology, otorhinolaryngology, hematology-oncology, and plastic surgery. In addition to medical experience and a literature review of the extracutaneous involvement, prevalence, progression and morbidity of PHACE syndrome, follow-up and family care were included.3 CUTANEOUS INVOLVEMENT At birth, IH can be absent or present as a precursor lesion that is represented by a pale or slightly erythematous or telangiectatic area. However, nearly all IHs are already visible at the end of the first month of life. Regarding its progression, 3 phases have been described: proliferation (with increased growth in the first 5 months of life), stabilization, and spontaneous involution (lasting for years).10,13 IHs that are associated with PHACE syndrome tend to be large (>5cm in diameter) or segmental—a term that has been proposed to describe the morphology of the hemangioma that affects one region and does not arise from a focal point. These IHs can present as telangiectasias, solitary lesions, confluent plaques, small papules that assume a specific distribution, and tumors with deeper involvement.14 Haggstrom et al. suspected a relationship between the facial location and extracutaneous involvement of an IH.9 Hence, the face was divided into 4 segments that are not related to the dermatomes or Blaschko lines but to the prominences of facial development: frontotemporal, frontonasal, maxillary, and mandibular. IHs on the frontotemporal and frontonasal segments bear a higher risk

Figure 2: Infantile hemangioma on the frontonasal and frontotemporal segments

Figure 4: Infantile hemangioma on the mandibular segment

Approximately 90% of the hemangiomas in PHACE syndrome are located on the cephalic segment. The face is the most commonly affected site, but lesions can develop on the scalp and postauricular and cervical regions. Large and segmental IHs on the occipital, upper thoracic, trunk, and proximal upper limb regions have also been described in PHACE syndrome.15 Large IHs on the infraorbital region that cause proptosis can be associated with the typical arterial anomalies in PHACE syndrome (Figure 5).16 Further, in the definition of possible PHACE syndrome, a small, nonsegmental IH or even the absence of cutaneous hemangiomas can be observed.7,17,18

VASCULAR AND STRUCTURAL INVOLVEMENT OF THE BRAIN Cerebrovascular changes in PHACE syndrome increase the risk for a cerebrovascular accident (CVA). Although it is rare, its incidence peaks when—in addition to CNS changes—there are cardiac malformations, such as coarctation of the aorta.19 Cerebrovascular accidents in the pediatric population have a multifactorial etiology, and patients with PHACE syndrome have several risk factors, such as possible vascular stenosis and occlusion, with the subsequent reduction in blood flow and thromboembolism, related to potential cardiac and supraaortic arterial lesions.3 In 2013, Metry et al. described the changes that were seen on brain magnetic resonance angiography (MRA) that predicted the

Severe narrowing or stenosis by >75% or lack of visualization of a main vessel (internal carotid, middle/anterior/posterior cerebral, basilar, and vertebral artery), with no evidence of collateral circulation